The technical field generally relates to internal combustion engine aftertreatment systems. Many current powertrain systems include an aftertreatment system in the exhaust of internal combustion engines to meet emissions regulations or to reduce emissions of undesirable exhaust gas constituents. A variety of aftertreatment systems include one or more catalytic components that experience degradation and/or reduced efficiency over time. Efficiency reductions can affect the conversion capability of the catalyst, and can also affect the storage capacity of the catalyst as an adsorption device. Often, the degradation of a catalyst does not introduce symptoms into the system that are ordinarily detectable. Further, detection of catalyst degradation can be complicated by the inclusion of multiple catalysts with differing degradation modes and rates, and by other complications such as cross-reading of multiple constituents by available composition sensors. Therefore, further technological developments are desirable in this area.